Spout for Flexible Fluid Reservoirs

ABSTRACT

A spout, particularly for flexible fluid reservoirs having opposing film panels, which minimizes stresses and abrasion resulting from manufacture and/or use of such reservoirs as well as enhances the strength of the weld/bond between the films and the spout. Spouts according to the invention include a generally cylindrical neck portion and a pair of opposed, generally triangular portions extending laterally there from that form a spout-film interface. This interface may be smooth and/or define depressions or holes to increase bond integrity. Spout embodiments of the invention also may include at least one, and preferably four, stress delocalizing feature(s) (“SDF”) to disperse material stress from edges of the spout-film interface that might form during use of the spout. Exemplary SDFs include flexible appendages, preferably at the apex of the triangular portions or at neck portions that form a portion of the spout-weld interfaces, which depend beyond the spout weld interface and into the reservoir.

BACKGROUND

In the field of flexible fluid reservoirs, particularly those comprised of two opposing panels of film selectively bonded together and incorporating a closable spout there between, attention has been directed to providing a secure and durable bond between the opposing panels of film and the spout. To enhance the nature of bond between the films and the spout, various approaches have been taken, including inclusion of surface features such as ribs, lands and/or grooves in the spout. While intended to address a perceived problem, such solutions were not without deficiencies. Moreover, little attention has been paid to the parameters surrounding the components, namely the spout and the film, with respect to the chemical properties thereof, and how best to optimize the same.

Turning first to issues pertaining to the physical attributes of the spout, spout rib geometries of the prior art generally produced excessive pressure at the weld interface, causing the material of the film subject to bonding with the spout to be displaced rather than bond with adjacent material on the spout rib. As this material was displaced, the remaining film at this location was considerably weakened, making it particularly subject to tearing.

In addition to the foregoing, prior art spouts often included a spout geometry that resulted in stress concentration at the spout corners (in most forms, the spout corners are considered those locations where the two generally opposing side surfaces of the spout's weld interface converge) when the reservoir was filled to near capacity. This intrinsic stress was greatly amplified when the reservoir was subjected to additional loads such as those experienced during “drop-testing”. In addition, conventional spout geometries, particularly in conjunction with stiff material selection, created high stress and abrasion of the film where it wrapped around the internal edge of the spout. This could result in premature failure of the film in this area.

As noted above, prior art spouts for flexible fluid reservoirs were not known to possess nor designed to possess melting temperatures that were matched to that of target films intended to be heat or radio frequency (RF) welded thereto. As a consequence, when such a spout and target film were subjected to such welding, desired bonding qualities were not always achieved. While one solution was to apply excess heat and/or pressure to accommodate these disparities, such a solution jeopardized material performance features, particularly in the more susceptible films. In certain instances, the melt temperature of the spout base material, such as high density polyethylene (HDPE), was 8° C. higher than the base material of the film's bonding layer, such as linear low density polyethylene (LLDPE), which resulted in a less than desirable final weld. As a consequence, flexible fluid reservoirs constructed from a film material that was welded to such a spout would experience preventable failures at this interface.

SUMMARY OF THE INVENTION

The invention is intended to provide a spout, particularly for flexible fluid reservoirs comprising opposing film panels such as the type broadly characterized as personal hydration reservoirs, which minimizes stresses and abrasion resulting from manufacture and/or use of such reservoirs as well as enhances the strength of the weld/bond between the films and the spout. The various invention embodiments minimize stresses to and abrasion of the film(s) comprising such reservoirs by exploiting certain spout geometries, and enhances the strength of the weld/bond between the films and the spout through material selection and spout surface characteristics, the details of which will be disclosed in the following paragraphs.

Each spout according to the invention comprises a generally cylindrical neck portion and a pair of opposed, generally triangular portions extending laterally there from that comprise a spout-film interface (also referred to herein as a “spout weld interface”). The neck portion includes an axis that is congruent with a longitudinal direction. Depending upon embodiments, the spout weld interface(s) may comprise one or more portions of the neck portion.

For purposes of this patent, the terms “area”, “boundary”, “part”, “portion”, “surface”, “zone”, and their synonyms, equivalents and plural forms, as may be used herein and by way of example, are intended to provide descriptive references or landmarks with respect to the article and/or process being described. These and similar or equivalent terms are not intended, nor should be inferred, to delimit or define per se elements of the referenced article, unless specifically stated as such or facially clear from the several drawings and/or the context in which the term(s) is/are used. Specifically as used herein, reference to a “weld interface” also includes the plural form and vice versa, and should not be inferred as limiting the embodiments or claimed invention to one form or the other based solely upon term selection and usage.

Certain spout embodiments of the invention comprise at least one material having a melting temperature, at least at spout weld interfaces thereof, which is closely matched to at least a portion of film-spout interfaces that that are part of a flexible fluid reservoir film (also referred to herein as “film weld interface(s)”). By closely matching the melt temperatures of the contacting materials at the film/spout weld interfaces, preferably at least within 5° C. and most preferably within 2° C., undesirable material displacement at the weld interfaces can be eliminated (presuming substantially homogeneous material temperatures). Research has shown that by reducing and preferably eliminating material displacement during the welding process, weld and/or material failures that might otherwise occur at the weld interface, and/or at areas of the film immediately adjacent to such interfaces, are significantly reduced. Thus, the film weld interfaces, which is usually, but not always, an inner surface of the film at such interface, comprises a material, preferably a LLDPE, that has a melting temperature closely matched to the melting temperature of the material at the spout weld interface, which is usually, but not always, an outer surface of the spout, which is also preferably a LLDPE. In such preferred compositions comprising LLDPE at the film and spout weld interfaces, a convenient means for matching melting temperature requirements is thereby provided.

In certain embodiments of the invention, pre-welded or exposed spout and/or film weld interface material may not be the primary or ultimate bonding media, but may be removed or overcome during the bonding process (as in the case of a volatile coating that is flashed or becomes a flux during bonding operations). However, in presently preferred embodiments, the pre-bonded spout and/or film weld interfaces comprise the closely matched melting temperature materials that form a suitable bond during a bonding or welding process comprising the application of heat and/or radio frequency (RF) energy. Thus, weld material selection is not constrained to that of the spout and/or film outermost or exposed surface, but to the functional material (surface) exposed during bonding operations.

Spout embodiments of the invention also may provide for enhanced spout weld interface surface and sectional characteristics as well as geometries. The surface characteristics comprise substantially flat and/or smooth surfaces, which permit uniform and/or lower material compression pressure to be used during welding, when compared to the prior art. By minimizing sectional thickness differences in adjacent portions of the spout weld interfaces, e.g., no substantial ridges, lands, protrusions or similar positive relief features reside on at least a substantial portion of the spout weld interfaces, displacement/extrusion of film weld interface material(s) is thus greatly minimized. As a consequence, film thickness and integrity at and proximate to the film weld interface can be maintained during and after the bonding process.

Certain embodiments of the immediately preceding type may also comprise negative relief surface features such as holes or depressions defined by the spout weld interface surfaces. As opposed to positive relief surface features, negative relief surface features such as depressions or holes beneficially permit air entrapped between film and spout weld interfaces during boding to escape or not adversely affect the desired weld, thus enhancing the film-to-spout bond. Additionally, such surface features also may accept displaced film/spout material, further enhancing the nature of the bond there between.

The skilled practitioner should appreciate that with respect to the foregoing, spouts having weld interfaces comprising lands and grooves are not equivalent to weld interfaces comprising a generally smooth surface (no positive relief features) but also defining negative relief features, which may include linear negative reliefs. In the former instance, the peaks of the lands do not constitute a “surface” within the meaning of this patent; “surface” as used herein denotes the nominal surface of the material. Moreover, negative surface features of the various invention embodiments are generally limited by the sectional thickness of the spout weld interface; positive relief features have no equivalent limitation.

In addition to the foregoing, spout embodiments of the invention also may comprise at least one stress delocalizing feature (“SDF”), which is particularly useful when spouts according to the invention are used with flexible fluid reservoirs having opposing film panels at the spout weld interface. As noted previously, displacement of reservoir panels at the spout weld interfaces causes the localization of stress along the free edge of the interfaces. This stress localization is often a precursor condition to failure of the weld/bond at the spout/panel weld interfaces. By incorporating at least one SDF, stresses otherwise directed to the interfaces are distributed over a wider area (of both the spout and the panels), thereby reducing the likelihood of failure at the interfaces.

One form of SDF comprises flexible appendages, preferably at the convergence of opposing sides of a spout (the apex of the triangular portions) or at neck portions that form a portion of the spout weld interfaces, which depend beyond the spout weld interface and into the reservoir. These flexible appendages are functionally hinged to the spout weld interfaces such that upon divergent flexing of the opposing film panels, resulting “peeling” forces from the panels to the spout are also imparted to the SDF, thereby reducing the imparted forces to the panels. Thus, the geometry of the SDFs is such that a weld between the spout and the panel experiences reduced peel stress in favor of shear stress. The remaining peel stress is generally directed to the spout itself, which is considerably stronger than the film.

Desirably, SDFs according to several invention embodiments do not have a constant longitudinal profile, nor necessarily a linear edge. A tapered form, preferably comprising a curvilinear edge, appears to most effectively delocalize forces that would otherwise be directed to the spout weld interface.

The prior art heavily relies upon spouts that have a generally rigid body, which is desirable at the spout neck portion where a cap may be fitted, but causes localized stress and abrasion of the flexible film panels when and where bonded thereto. Selected embodiments of the invention may also therefore include spout edges and/or portions of the spout weld interfaces that are flexible in comparison to the neck portion of the spout. Such an arrangement significantly reduce stress and abrasion of the film panels in this area by permitting portions of the spout to flex in response to flexing of the film panels, as opposed to localizing stresses at the spout weld interface periphery. This flexing ability also constitutes a form of an SDF.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the invention shown welded to a flexible fluid container;

FIG. 2 is a side elevation view of the first embodiment of the invention with alternative weld interface treatments, the left side illustrating a spout weld interface comprising a plurality of negative relief elements and the right side illustrating a spout weld interface comprising a plurality of holes;

FIG. 3A is a cross section taken substantially along the lines 3A-3A in FIG. 2;

FIG. 3B is a cross section taken substantially along the lines 3B-3B in FIG. 2;

FIG. 4 is an end elevation view of the first embodiment;

FIG. 5 is a perspective view of a second embodiment of the invention;

FIG. 6 is a side elevation of the second embodiment;

FIG. 7 is an end elevation view of the second embodiment; and

FIG. 8 is a bottom plan view of the second embodiment.

DESCRIPTION OF INVENTION EMBODIMENTS

Preface: The terminal end of any numeric lead line in the several drawings, when associated with any structure, reference or landmark described in this section, is intended to representatively identify and associate such structure, reference or landmark with respect to the written description of such object. It is not intended, nor should be inferred, to delimit or define per se boundaries of the referenced object, unless specifically stated as such or facially clear from the drawings and the context in which the term(s) is/are used. Unless specifically stated as such or facially clear from the several drawings and the context in which the term(s) is/are used, all words and visual aids should be given their common commercial and/or scientific meaning consistent with the context of the disclosure herein.

Turning then to the several drawings, wherein like parts are numbered the same, and more particularly to FIGS. 1-4, a first embodiment of the invention is shown. Here, spout 10 includes neck portion 20 having external threads 26 formed on outer surface 24 thereof. Neck portion 20 further includes portions 28 that comprise part of spout weld interfaces 30.

Spout weld interfaces 30 generally include extensions 32 a and 32 b, each having spout weld interface surfaces 34 a and 34 b. These surfaces, in conjunction with neck portions 28, form the entirety of the surface that is bonded or welded to opposing film panels 82 a and 82 b of reservoir 80. Each extension 32 further includes peripheral edges 36 and converging edge 38. It should be noted that peripheral edges 36 and adjacent portions of spout weld interfaces 30 are somewhat flexible in that they are able to converge and diverge relative to each other; this is a result of not having any spanning or structural element restricting such movement. This ability to flex relative to neck portion 20, for example, provides one means for reducing stress and abrasion to film panels 82 a and 82 b at film weld interfaces 90, and therefore constitutes a form of a Stress Delocalization Feature or SDF.

Returning to spout weld interface surfaces 34 a and 34 b, FIGS. 3, 3A and 3B illustrate several forms in which these surfaces may exist. In addition to a smooth surface, spout weld interface surfaces 34 a and 34 b may also comprise negative relief features 40 such as a plurality of dimples 42 or holes 44. These negative relief features provide a means for beneficially mitigating the effects of gas(es) trapped between opposing film panels 82 a and 82 b of reservoir 80 and spout weld interface surfaces 34 a and 34 b during the welding/bonding process and/or providing a location for material displacement resulting from such process.

The embodiment shown in FIGS. 1-4 further comprises flexible appendages 50, each having extending body portion 52, which is linked to extensions 32 via hinge element 54, and curvilinear periphery 56. Opposing film panels 82 a and 82 b of reservoir 80 may or may not be bonded to appendages 50; in either instance, if hydrostatic pressure within reservoir 80 causes opposing film panels 82 a and 82 b to diverge, then extending body portions 52 will pivot about hinge elements 54 and maintain contact with the panels. As a consequence, separation forces that otherwise would be solely directed to the panels, which would cause localization of peeling forces at peripheral edges 36, is dispersed partly to flexible appendages 50 which in turn compressively coact against portions of opposing film panels 82 a and 82 b that otherwise would not be affected. In this manner, flexible appendages 50 function as SDFs.

In FIGS. 5-8, a second embodiment of the invention is shown that is substantially similar to the first illustrated embodiment, except that flexible appendages 50′ are positioned proximate to portions 28 of neck portion 20. Because flexible appendages 50 or 50′ are intended to function as SDFs, greatest benefit there from can be achieved with such appendages are positioned at or adjacent to portions of spout weld interfaces 30 that are less flexible than other portions thereof. In many instances, the least flexible portions of spout weld interfaces are at converging edges 38 or portions 28. In this second embodiment, flexible appendages 50′ are positioned at or adjacent to portions 28 (in the first embodiment, flexible appendages 50 were positioned at or adjacent to edges 38). Burst test data have shown that similar stress delocalization occurs in the second embodiment when compared to the first. In most other respects, the two embodiments are similar. 

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 11. A spout for flexible fluid reservoirs, the reservoirs comprising at least one film material having an inner surface, an outer surface, and at least one film weld interface having a material with a known melting temperature T_(F), the spout comprising: a substantially cylindrical neck portion having an axis congruent with a longitudinal direction; and at least one spout weld interface having an exposed surface and extending from the neck portion, wherein the at least one spout weld interface comprises a material with a known melting temperature T_(S) and has at least one stress delocalizing feature.
 12. The spout of claim 11, wherein the at least one stress delocalizing feature comprises a peripheral edge characterized as flexible relative to the neck portion.
 13. The spout of claim 11, wherein the at least one stress delocalizing feature comprises at least one generally flexible appendage extending in a longitudinal direction from the at least one spout weld interface.
 14. The spout of claim 13, wherein the at least one generally flexible appendage is at or adjacent to an apex of the at least one spout weld interface.
 15. The spout of claim 13, wherein the at least one generally flexible appendage is at or adjacent to the neck portion of the at least one spout weld interface.
 16. The spout of claim 13, wherein the at least one generally flexible appendage comprises a curvilinear peripheral edge.
 17. The spout of claim 13, wherein the at least one generally flexible appendage comprises an irregular longitudinal profile.
 18. The spout of claim 13, wherein the at least one generally flexible appendage is at least partially mechanically linkable to at least a portion of the at least one film material of the reservoir.
 19. The spout of claim 13, wherein the spout comprises four generally flexible appendages.
 20. The spout of claim 11, wherein the at least one stress delocalizing feature comprises a peripheral edge characterized as flexible relative to the neck portion, and at least one generally flexible appendage extending in a longitudinal direction from the at least one spout weld interface.
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 22. The spout of claim 11, wherein the difference between T_(S) and T_(F) is ±5° C.
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 24. The spout of claim 11, wherein the at least one spout weld interface material is of the same type as the at least one film weld interface material.
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 35. The spout of claim 11, wherein the at least one spout weld interface comprises an exposed surface wherein at least a major portion of the exposed surface is characterized as smooth.
 36. The spout of claim 35, wherein the at least a major portion of the exposed surface is further characterized as defining a plurality of holes.
 37. The spout of claim 35, wherein the at least a major portion of the exposed surface is further characterized as defining a plurality of negative relief features.
 38. The spout of claim 35, wherein the at least a major portion of the exposed surface is further characterized as defining a plurality of holes and negative relief features.
 39. The spout of claim 11, wherein the at least one film weld interface material is between the inner surface and the outer surface of the film.
 40. The spout of claim 11, wherein the at least one stress delocalizing feature comprises a peripheral edge characterized as flexible relative to the neck portion and at least one generally flexible appendage extends in the longitudinal direction from the at least one spout weld interface, and wherein the difference between T_(S) and T_(F) is ±5° C. 